Scoping Out the Planet

KAY CHERNUSH
At two years old and $37 million invested, EarthScope is like a young Little League team with the game tied in the second inning--the players are still learning to work together, and the parental units are watching closely. But the game is just getting started.

The passionate, pat-you-on-the-back coach is Greg van der Vink, geophysicist by training, visiting Prince¿ton University professor, and the first project director of the most ambitious earth science project ever attempted. If successful, EarthScope will measure the movement and deformation of the earth below the contiguous U.S. and Alaska with a level of detail and data accessibility never seen in geophysics. The hope is that a clearer understanding of the forces that shape the environment will translate into better assessment of earthquake and volcanic hazards and more precise knowledge of the country's natural resources.

When I meet the 48-year-old Greg van der Vink--known as GVDV among colleagues--at a June meeting of the Incorporated Research Institutions for Seismology (IRIS), a consortium of universities and research bodies, I ask for a sports analogy to explain EarthScope. "I wondered if that would come up," he chuckles. The first time van der Vink testified before Congress--in the mid-1980s as a congressional fellow fresh out of graduate school--a senator advised him to use a sports analogy to explain everything in three minutes or less, the idea being that that is about the amount of time you have to make your case. Now a sports analogy is part of the final exam for his Prince¿ton students.

Not surprisingly, van der Vink wants his students to be both scientifically and politically literate. Besides his congressional fellowship, he has been an adviser to Congress and President Bill Clinton on nuclear arms control and treaty verification and a reviewer for the Council on Foreign Affairs to improve how scientific information is used to formulate international policy.

Following his work on Capitol Hill, van der Vink served as the director of IRIS for 14 years, where he was part of the initial planning process for EarthScope. He and his colleagues wanted a way to fill the information gaps in earth science, to look deeper into the earth with better resolution. Today geoscientists rely mostly on data from quakes, gathered only if the limited number of instruments is near the sites--conditions somewhat dependent on chance. Alternatively, they conduct the occasional active source experiment, in which sound waves are created and recorded--conditions somewhat dependent on funding.

Nearly a decade of discussions and workshops, attended by hundreds of geoscientists from more than 50 universities and a dozen state and federal agencies, led to the final EarthScope proposal, which was funded by Congress in 2003. "This will shift the future of earth science," van der Vink declares. "EarthScope will provide a new source of data for the next decade." He adds, "In the future, it may not be a science limited by [the lack of] data."

When it is complete in 2008, EarthScope's web of instruments will provide public data for geoscience, not unlike the way the human genome sequencing effort has for biology. EarthScope will gather information on three scales.

At the smallest scale, or fault level, is the San Andreas Fault Observatory at Depth (SAFOD), a four-kilometer-deep hole that is drilled into the mountains 300 kilometers south of San Francisco. SAFOD, set to be finished in 2007, has drilled down 3,200 meters next to the area that has ruptured seven times since 1857 (including the most recent magnitude 6 Parkfield earthquake in 2004). On August 2 drilling reached the fault zone, where scientists plan to install seismic instruments and take rock and fluid samples.

At the middle scale is the plate boundary level, where the Plate Boundary Observatory (PBO) will image and characterize the slow deformation of the earth along the western U.S. and Alaska. Roughly 1,000 Global Positioning System (GPS) instruments will be installed in a gridlike pattern from the edge of the Pacific Coast to the Rocky Mountains and from Alaska to Mexico (not including Canada). Mounted on four four-meter-long legs for stability, these instruments will communicate with GPS satellites to measure movement on the surface of the earth. In addition, 175 devices will be clustered along fault zones and magmatic centers to measure strain on the surface and at depth. Crews finished installing instruments on Akutan Volcano in Alaska in early July.